Expansion joint



June 2l, 1938. f R. R. ROBERTSON EXPANSION JOINT Filed Nov. 21, 1936 E RoEm- R. ROBERTSON M Aj 5 Patented June 2l, 1938 EXPANSION JOINT Robert R. Robertson, Chicago, Ill., assignor to The Translode Joint Company, Chicago Heights, Ill., a, corporation of Illinois Application November 21, 1936, Serial No. 111,974

12 Claims.

This invention relates to an improved road expansion joint adapted to be embedded between adjacent concrete road slabs, said joint including in combination a. precast plastic filler board adapted to be mounted upon a road subgrade and having openings provided at spaced intervals throughout the length of the ller board for the reception of adjustable load transmission units. each of which consists of a pair of core plates having portions thereof formed to provide double looped sections, with the looped sections of one plate slidably intertting the looped sections of the adjacent plate, said unit also including apertured dowel plates engaged in the looped portions of the core plates and projecting upwardly in opposite directions to permit the split deflected ends thereof to be embedded in the concrete slabs on opposite sides of the joint filler board to serve as a means for the transmission of loads from one road slab across the expansion, joint to the adjacent road slab. p

It is an object of this invention to provide a road expansion joint comprising a preformed` which project outwardly in opposite' directions' from the joint and have the ends thereof formed to anchor the dowel plates in the concrete on opposite sides of the filler board.

A further object of the invention is the provision of a road expansion joint in which an apertured filler board has a plurality of load transmission units projecting .therethrough to permit parts of the units to be embedded in the concrete on opposite sides of the joint.

It is furthermore an object of this invention` to provide a road expansion joint including a preformed filler board having openings therein for thereception of spaced load transmitting units'` including anchoring plates having openings therein for the reception of retaining stakes or pins for holding the joint forming mechanism in position for the pouring of concrete on opposite sides of the joint.

It is an important object of -this invention to provide an improved concrete road expansion joint mechanism including a preformed plastic iiller board having openings provided at spaced a road subgrade.- 15

Other' and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawing.

The invention (in a preferred form) is illus- 2o trated in the drawing `and hereinafter more fully described.

On the drawing: A

Figure 1 is a fragmentary side elevation of an expansion joint forming mechanism embodying 25 the principles of this invention and disclosing the apertured filler board with the load transmitting units engaged therein and showing one of the openings unlled. y

Figure 2 is an enlarged sectional view taken on line IVI-II of Figure 1 showing the expansion joint forming mechanisms embeddedin the concrete road slabs and supported on the road subgrade, and furthermore illustrating the retaining stakes which may be left in position as indicated by the full line showing of one of the stakes or such stakes may be removed after the pouring of concrete from the dotted line position illustrated.

Figure 3 is a fragmentary top plan view of the joint mechanism taken on line III- III of Figure 1.

Figure 4 is an enlarged fragmentary part sectional. and part elevational View of one of the load transmission units and illustrating portions of the dowel plates secured in position in looped portions of the sections which slidably engage in receiving pockets forming part of the sections.

Fig. 5 is a vertical detail section taken on line .V-V of Figure 4.

As shown on the drawing: y

The expansion joint as illustrated in Figures 1 and 2 is formed by means of joint forming mechanisms adapted to be supported on a. road subgrade I for embedding between concrete road slabs 2.

The improved expansion joint forming mechanism comprises a preformed or precast plastic filler board 3 adapted to be constructed out of asphalt, sponge rubber, cork, or any other suitable compressible material, such for example as a compressible material known to the trade as Flexcel. The iler board or core member 3 is provided with a plurality of spaced openings 4 for the reception of load transmission units, one of which is engaged in each of the filler board openings 4.

Each of the load transmission units comprises a pair of oppositely positioned metal-core plates 5 adapted to be positioned against opposite sides of the illler board 3 adjacent one of the openings 4. Each of the metal plates 5 has the middle portion thereof deflected or formed to` provide an intermediate S-section in the form of outwardly projecting loops 6 and I connected by means of a common'plate 8 which integrally connects the two looped portions 6 and 'l as clearly illustrated in Figure 4. The plate sections have the looped portions B thereof thicker than the 'looped portions I to permit the looped portion 1 of one of the plate sections to be slidably projected into the thicker looped` portion 5 of the opposite plate section. As shown in Figure 2, the two plate sections are reversed with respect to one another, thereby permitting the thinner looped portions I to project in opposite directions in overlapping relation with respect to one another through one of the filler board openings 4.

The top plate of each of the looped portions 6 is provided with integral side extensions which are deilected downwardly to provide side walls or closure flanges 9. The looped portions 5 with the side walls or anges 9 provide pockets or ,sockets from which the concrete is prevented from entering by means of the side walls or flanges 9. The opening in each of the sockets 8-9 is closed by means of the looped port'ion 1 of an adjacent core plate 5.

Projecting into the thinner looped portion I of each of the plate sections is one end of a dowel plate or dowel bar I0 provided with one or more openings II for the reception of inwardly directed detents or projections I2 provided within each of the looped portions 1 as clearly villustrated in Figure 4. The locking detents or projections I2 seating in the openings Il serve to lock the end of the dowel plate III in place. Each of the dowel plates I0 lies adjacent the looped portion 6 and projects outwardly beyond the end of said looped`portion into the concrete road slab. The outer end`of each of the dowel plates i0 .is split longitudinally to provide anchoring ngers for blades I3 vwhich project upwardly and downwardly with respect to one another. Each of the dowel plates I0 is provided with an opening I4 for the reception of a retaining or supporting stake i5 the lower tapered vend of which is adapted to be driven into the subgrade I on opposite sides of the ller board 3 for securing the joint forming mechanisms in position upon the subgrade ready for the pouring of concrete to form the road slabs- 2.

The dowel plates or bars I0, which are con-u nected in the respective looped portions 'i of the reversed plate sections 5, serve to anchor the plate sections in the opposite road slabs 2 so that the telescoping or interfitting looped portions 6 and 'l of the interltting plate sections are adapted to have slidable movement with respect to one another with the contraction and expansion of the road slabs due to temperature changes.

The plate sections 5 may be shipped to location with the apertured ends of the dowel plates Ill locked in the looped portions 'l by means of the detents I2. The load transmission units may be assembled on the job with the plate portions arranged on opposite sides of the filler board 3 and having the looped portions I projecting through the board openings 4 thereby positioning the projecting ends of the -dowel plates I0 on opposite sides of the filler board 3 in position to receive retaining pins or stakes I5 projected through the openings I4 to hold the joint forming mechanisms securely braced in position uponthe road subgrade prior to the pouring of concrete on opposite sides of the joint mechanisms to form the road slabs 2 which embed the joint forming mechanisms. The retaining stakes or pins I5 may be left in position as illustrated in Figure 2, or if' desired, the same may be removed from the concrete before ithas cured too much.

The improved joint forming mechanism is of simplied form including the ller board which has the load transmission units arranged at spaced intervals along the length of the filler board thereby connecting the opposite road slabs at spaced intervals along the length of the joint for the transmission of loads from one slab to the other through the joint.

While the load transmission units associated with the i'lller board are illustrated and described as being located at spaced intervals in a longitudinal center line of the filler board, it will of course be understood that the load transmission units may be staggered with respect to one another and that any desired number of the same may be employed.

With the looped portions 5 of the load transmission plate sections 5 provided with the closure flanges or side walls 9, concrete is prevented from entering4 the looped portions 5 thereby permitting slidable interiltting movement of the respective looped portions 1 in the looped portions 5 of adjacently positioned plate sections 5.

In the improved form of load transmitting mechanisms hereinbefore described, it will be noted that the amount of metal required for the formation of the expansion joint is materially less than that required in expansion joints wherein continuous core plate sections are provided to extend throughout the entire length of the expansiongjoint. l

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the .principles of this invention, and it is therefore not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I claim as my invention'. y y

1. An expansion joint forming mechanism comprising a preformed plastic illler board having spaced openings therein, double looped load transmission units projecting from opposite sides into intertting relation with one another through the openings of the illler` board, and anchoring dowel members projecting in opposite direction through the filler board and anchored in the double looped portion of the load transmitting units.- v

2. A road `expansion joint for embedding between adjacent concrete'road slabs and comprising a preformed plastic filler board having openings therein, metal plates positioned against opposite sides of the ller board adjacent the openings therein, each of said metal plates having a portion thereof folded upon itself to form a two loop. section with one of the looped-sections embedded in one of the road slabs and the other looped section projecting through a filler board opening and into the other road slab within a looped portion of an opposite metal plate.

3. A road expansion joint comprising a preformed plastic ller board having spaced openings therein, metal plates positioned on opposite \sides of said Vboard adjacent the openings, said plates folded to form looped portions projecting in opposite directions transversely through the openings in the filler board, and dowel bars locked in looped portions of the plates and projecting outwardly in opposite directions beyond the sides of the plates.'

4. A road expansion joint comprising a preformed plastic ller board having spaced openings therein, metal plates positioned on opposite sides of said board adjacent the openings, said plates folded to form looped portions projecting in opposite directions transversely through tthe openings in the filler board, dowel bars` rigidly' secured in looped portions of the plates and projecting outwardly in opposite directions beyond the sides of the plates, and anchoring members formed on the projecting ends of the dowel bars.

5. A road expansion joint comprising a preformed nller board having spaced openings therein, metal plates on opposite sides of the filler board adjacent the openings, said plates folded to form looped portions projecting through theopenings in the filler board, dowel members projecting through the openings in the filler board and into looped portions of said plates, means for locking the dowel members in the looped portions of the metal .plates into which they project, anchoring members formed on the projecting ends of the dowel members, said dowel members having openings therein, and stake members for engagement through the dowel member openings for mounting the road expansion joint mechanisms inposition upon a road subgrade.

6. An expansion joint forming mechanism including in combination a load transmitting unit comprising a pair o`f plates, each of said plates having portions thereof deflected outwardly from opposite sides thereof to form looped sections, connected by a Acommon plate forming part of each of said looped sections and projecting through the plane of the plate from which it is. formed, and closure plates forv the sides of one of the looped sections of each of said plates. f

7. An'expansion joint forming mechanism including in combination a load transmitting unit comprising a pair of plates, each of said platesv having portions thereof deflected-outwardly from opposite sides thereof to form looped sections connected by a common plate forming part of each of -said looped sections and projecting through the plane of the plate from which it is formed, closure plates for the sides o f one o! the dowel bars.

looped sections of each oi' said plates. a dowel bar secured in the other of the-looped sections of each of said plates, and anchoring members formed on the projecting end of each` of the 8. Aroad expansion joint comprising a. preformed plastic llen board having an opening therein, a pair of plates positioned on opposite sides of the filler board adjacent the opening, both of said plates having portions thereof formed to project through the opening in the filler board, and anchoring members projecting through the opening in the filler board and rigidly secured in the portions .of the plates which project thr'oug the opening in said ller board.

9. A road expansion joint comprising a preformed plastic filler board having an opening therein, ay pair of plates positioned on opposite sides of the filler board adjacent the opening, each of said plates having portions thereof formed to project through the opening in theller board, anchoring members projecting through the opening in the ller board and engaged in the portions of the plates which project throughjthe opening. in the filler board, and closure, walls formed on opposite sides of one of the looped sections of each of the plates to enclose the open sided looped. section of the adjacent plate.

.10. An expansion joint forming mechanism including in combination a load transmitting unit comprising a pair of plates, each of said plates having portions thereof deflected outwardly from opposite sides thereof to form looped sections with the looped sections of adjacent plates slidably interfitting one another, a dowel bar rigidly secured in one of the looped sections of each of said plates, and closure members forme'd on the sides of the other looped section of each of said plates.

11. An expansion joint forming mechanism including in combination a load transmitting unit comprising a pair of plates, each of said plates having` portions thereof deflected outwardly from opposite sides thereof to form looped sections with the looped sections of said plates-slidably intervfitting one'another, a dowel plate in one of the looped sections of each of said plates, closure members formed on the sides of the other looped section of each of said plates, and means for locklng the dowel plates in the respective looped sections in which they are engaged.

12.` An expansion joint forming .mechanism lncluding inv combination a load transmitting unit comprising a pair of reversed interfitting sections each consisting of a plate, a socket projecting from'one side of the plate and closed at the tcp, bottom, both sides, and at one end. a looped portion projecting from the opposite side of the' dowel member.

l ROBERT R.. ROBERTSON. 

